Not Applicable
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Not Applicable
The present invention relates to generating signal paths through a switching network, and more particularly, to generating signal paths from a variety of test sources, through a switching network, to a Device Under Test (DUT), as a function of commands that are written in a language associated with, and descriptive of, the DUT. Such testing is also referred to herein as xe2x80x9cdevice oriented testing.xe2x80x9d
FIG. 1 shows an exemplary prior art testing system 10 for testing an electrical device 12 (also referred to herein as DUT). Such systems allow automatic testing of electrical devices in an efficient, repeatable manner, with little or no input from the person running the test. Such a testing system 10 has great utility for an electrical device manufacturer who produces a large number of devices each day that must be tested for functionality prior to being shipped. In general, such testing systems 10 include a plurality of testing devices 14 (also referred to herein as testing resources) that generate test signals to be applied to the DUT 12, and/or receive response signals from the DUT 12. The testing devices 14 that produce test signals also typically measure the signals as they are generated and record test signal measurements, and the testing devices 14 that receive the response signals measure the response signals and record the response measurements. The testing devices 14 are electrically coupled to a switching network 16, which is electrically coupled to the DUT 12. A controller 18 is electrically coupled to the switching network, and provides control signals to the switches (also referred to herein as relays) to selectively connect testing devices 14 to individual input/output (I/O) ports of the DUT 12. The switching network thus allows each I/O port of the DUT to be tested by multiple testing devices 14.
In typical prior art systems, the controller 18 is a computer system, and a test technician (also referred to herein as xe2x80x9cthe userxe2x80x9d) fashions test procedures for the DUT in code written on the computer. For example, the test technician may determine that one portion of the test procedure for a particular DUT 12 should be to connect a first testing device to each of the I/O ports of the DUT 12. For the first I/O port of the DUT 12, the technician must determine which relays of the switching network 16 must be closed to create a path from the testing device to the first I/O port. The technician then executes code on the computer that causes the computer to send control signals to the switching network 16, closing the relays that create a path from the testing device to the first I/O port. Once the first testing device completes the test of the first I/O port, the technician executes code that eliminates the path created by the previous step, and then executes further code to create a path from the first testing device to the second I/O port. This procedure repeats until all I/O ports of the DUT 12 have been connected to and tested by the first testing device.
One disadvantage to this procedure for testing a DUT is that it places a significant burden on the testing technician, especially when the DUT 12 has a large number of I/O ports, and when the switching network is complex and includes a large number of relays. For each path from a testing device to a DUT I/O port, the technician must determine which relays must be closed to implement the path, then write and execute code that closes those relays. Further, any changes in the testing procedure involves keeping track of which relays are already closed, which of those must be opened, and which open relays must be closed, in order to create the new path.
Another disadvantage to this procedure is that it adds a significant probability of incurring errors during testing. Because the test technician must resolve each path manually, occasionally the wrong path will be created due to an inevitable programming error, and the procedure will consequently not test that which was intended.
It is an object of the present invention to substantially overcome the above-identified disadvantages and drawbacks of the prior art.
The foregoing and other objects are achieved by the invention which in one aspect comprises a method of sequentially connecting one or more testing devices to I/O ports of a DUT through a switching network, so as to execute a predetermined testing procedure associated with the DUT. The method includes generating a switching network map defining one or more connections within the switching network necessary to implement each of a plurality of electrical paths from an input of the switching network to an output of the switching network, wherein each of the plurality of electrical paths is representative of a connection of one of the testing devices to one of the I/O ports of the DUT. The method further includes receiving one or more commands, wherein each of the commands uniquely specifies an electrical path connecting a particular testing device to a particular I/O port of the DUT. For each of the one or more commands, the method compares the command to the switching network map so as to identify a corresponding electrical path through the switching network, and implements the corresponding electrical path associated the command through the switching network. The method further includes sequentially implementing the electrical paths corresponding to the one or more commands in a predetermined order.
Another embodiment of the invention further includes assigning a unique path name to each of the electrical paths, such that each commands specifies a particular electrical path via the path name.
Another embodiment of the invention further includes sequentially implementing the electrical paths associated with the one or more commands through the switching network in an order corresponding to a chronological order of the one or more commands.
Another embodiment of the invention further includes opening and closing selected switching devices within the switching network.
Another embodiment of the invention further includes programming a computer system to issue the commands in the predetermined order.
Another embodiment of the invention further includes connecting one or more testing devices to multiple DUT sites via the switching network.
Another embodiment of the invention further includes associating each of the electrical paths with a name that is (i) descriptive of the path and (ii) related to DUT.
Another embodiment of the invention further includes
In another aspect, the invention comprises a system for sequentially connecting one or more testing devices to I/O ports of a DUT through a switching network, so as to execute a predetermined testing procedure associated with the DUT. The system includes a switching network map defining one or more connections within the switching network necessary to implement each of a plurality of electrical paths from an input of the switching network to an output of the switching network, wherein each of the plurality of electrical paths is representative of a connection of one of the testing devices to one of the I/O ports of the DUT;
a controller for (i) receiving one or more commands, wherein each of the commands uniquely specifies an electrical path connecting a particular testing device to a particular I/O port of the DUT, (ii) comparing each of the commands to the switching network map so as to identify a corresponding electrical path through the switching network, and implementing the corresponding electrical path associated the command through the switching network, and (iii) sequentially implementing the electrical paths corresponding to the one or more commands in a predetermined order.
In another embodiment of the invention, the switching network includes at least two sub-networks electrically coupled so as to form the plurality of electrical paths.
In another embodiment of the invention, the sub-networks include an SCM and a DUT board.
In another embodiment of the invention, each of said one or more commands includes a pin name that is (i) descriptive of the path and (ii) related to DUT.